In the art world, the question of who shapes public taste is a perennial favourite. Magazines like to rank the heavyweights. Last year’s ArtReview’s Power 100 included an assortment of global dealers and collectors; Ai Weiwei and Pussy Riot made it too. While such ladders of influence invariably include museum staff and art historians, it is clear that Jenny Holzer’s aphoristic ‘Truism’, Money Creates Taste, was prescient.